On the historical origins of the contemporary notion of incommensurability: Paul Feyerabend’s assault on conceptual conservativism

This paper investigates the historical origins of the notion of incommensurability in contemporary philosophy of science. The aim is not to establish claims of priority, but to enhance our understanding of the notion by illuminating the various issues that contributed to its development. Kuhn developed his notion of incommensurability primarily under the influence of Fleck, Polanyi, and Köhler. Feyerabend, who had developed his notion more than a decade earlier, drew directly from Duhem, who had developed a notion of incommensurability in 1906. The idea is that in the course of scientific advance, when fundamental theories change, meanings change, which can result in a new conception of the nature of reality. Feyerabend repeatedly used this notion of incommensurability to attack various forms of conceptual conservativism. These include the logical positivists’ foundational use of protocol statements, Heisenberg’s methodological principle that established results must be presupposed by all further research, attempts to separate philosophical accounts of ontology from physics, Bohr’s principle of complementarity, and logical empiricist accounts of reduction and explanation. Focusing on the function of the notion of incommensurability common to Feyerabend’s various critiques explicates Feyerabend’s early philosophy as a series of challenges to forms of conceptual conservativism.     

Incommensurability reconsidered

In his later writings Kuhn reconsidered his earlier account of incommensurability, clarifying some aspects, modifying others, and explicitly rejecting some of his earlier claims. In Kuhn’s new account incommensurability does not pose a problem for the rational evaluation of competing scientific theories, but does pose a problem for certain forms of realism. Kuhn maintains that, because of incommensurability, the notion that science might seek to learn the nature of things as they are in themselves is incoherent. I develop Kuhn’s new account of incommensurability, respond to his anti-realist argument, and sketch a form of realism in which the realist aim is a pursuable goal.     

Thought styles and paradigms—a comparative study of Ludwik Fleck and Thomas S. Kuhn

At first glance there seem to be many similarities between Thomas S. Kuhn’s and Ludwik Fleck’s accounts of the development of scientific knowledge. Notably, both pay attention to the role played by the scientific community in the development of scientific knowledge. But putting first impressions aside, one can criticise some philosophers for being too hasty in their attempt to find supposed similarities in the works of the two men. Having acknowledged that Fleck anticipated some of Kuhn’s later theses, there seems to be a temptation in more recent research to equate both theories in important respects. Because of this approach, one has to deal with the problem of comparing the most notable technical terms of both philosophers, namely “thought style” and “paradigm”.This paper aims at a more thorough comparison between Ludwik Fleck’s concept of thought style and Thomas Kuhn’s concept of paradigm. Although some philosophers suggest that these two concepts are essentially equal in content, a closer examination reveals that this is not the case. This thesis of inequality will be defended in detail, also taking into account some of the alleged similarities which may be responsible for losing sight of the differences between these theories.     

Thought styles and paradigms: A comparative study of Ludwik Fleck and Thomas S. Kuhn

At first glance there seem to be many similarities between Thomas S. Kuhn’s and Ludwik Fleck’s accounts of the development of scientific knowledge. Notably, both pay attention to the role played by the scientific community in the development of scientific knowledge. But putting first impressions aside, one can criticise some philosophers for being too hasty in their attempt to find supposed similarities in the works of the two men. Having acknowledged that Fleck anticipated some of Kuhn’s later theses, there seems to be a temptation in more recent research to equate both theories in important respects. Because of this approach, one has to deal with the problem of comparing the most notable technical terms of both philosophers, namely “thought style” and “paradigm”.This paper aims at a more thorough comparison between Ludwik Fleck’s concept of thought style and Thomas Kuhn’s concept of paradigm. Although some philosophers suggest that these two concepts are essentially equal in content, a closer examination reveals that this is not the case. This thesis of inequality will be defended in detail, also taking into account some of the alleged similarities which may be responsible for losing sight of the differences between these theories.     

Scientific realism and the semantic incommensurability thesis

This paper reconsiders the challenge presented to scientific realism by the semantic incommensurability thesis. A twofold distinction is drawn between methodological and semantic incommensurability, and between semantic incommensurability due to variation of sense and due to discontinuity of reference. Only the latter presents a challenge to scientific realism. The realist may dispose of this challenge on the basis of a modified causal theory of reference, as argued in the author’s 1994 book, The incommensurability thesis. This referential response has been the subject of a charge of meta-incommensurability by Hoyningen-Huene et al. (1996), who argue that the realist’s referential response begs the question against anti-realist advocates of incommensurability. In reply, it is noted that a tu quoque rejoinder is available to the realist. It is also argued that the dialectical situation favours the scientific realist, since the anti-realist defence of incommensurability depends on an incoherent distinction between phenomenal world and world-in-itself. In light of such incoherence, and a strong commonsense presumption in favour of realism, the referential response to semantic incommensurability may be justifiably based on realism.     

Incommensurabilities in the work of Thomas Kuhn

I distinguish between two ways in which Kuhn employs the concept of incommensurability based on for whom it presents a problem. First, I argue that Kuhn’s early work focuses on the comparison and underdetermination problems scientists encounter during revolutionary periods (actors’ incommensurability) whilst his later work focuses on the translation and interpretation problems analysts face when they engage in the representation of science from earlier periods (analysts’ incommensurability). Secondly, I offer a new interpretation of actors’ incommensurability. I challenge Kuhn’s account of incommensurability which is based on the compartmentalisation of the problems of both underdetermination and non-additivity to revolutionary periods. Through employing a finitist perspective, I demonstrate that in principle these are also problems scientists face during normal science. I argue that the reason why in certain circumstances scientists have little difficulty in concurring over their judgements of scientific findings and claims while in others they disagree needs to be explained sociologically rather than by reference to underdetermination or non-additivity. Thirdly, I claim that disagreements between scientists should not be couched in terms of translation or linguistic problems (aspects of analysts’ incommensurability), but should be understood as arising out of scientists’ differing judgments about how to take scientific inquiry further.